Oh man, has she lost the plot. Back to the basics, believe nothing they say and only half of what they do. She wants her son? Her actions show she wants nothing but to live the single, unencumbered life and she is not afraid to throw away your precious son.
I am in awe of your fortitude and endurance, you've made clear, careful decisions that have protected your son and continue to be a wonderful parent. Your wife is bordering on mentally ill at this point. She is acting like an addict that is willing to throw away anything for that next high.
Here's the thing, divorce does not necessarily close a door forever, it does protect you legally and also makes sure your son is being parented by the safest, most stable parent. There have been quite a few marriages that have reconciled post divorce and even remarriages. So think of this as a very far-off option, a plan Z if you will. Strength and honor in the meantime.
M 10yrs T 13yrs BD #1Oct 2015-PA between WAH and COW BD #2 April 2016-WH resumed PA, she broke it off Jan 2 2017 WH says he wants divorce April '17-Letting go 2018 D busted DD8, DS6, DS3